Twitter is seizing more control over tweets as it tries to turn its free
service into a profitable online advertising business, provoking a backlash
from the web industry.

Where it once allowed outside firms to exploit its data to create new applications, it is now introducing tight restrictions designed to keep traffic to itself.

In recent weeks it has blocked the professional networking website LinkedIn, Instagram, Facebook’s smartphone camera app, and the popular blogging service Tumblr from piggybacking on its membership. All three have been forced to withdraw features that allowed their own members to easily connect with their Twitter contacts.

The strict new regime represents a strategic about-face for Twitter, which previously adopted a liberal, open approach and sought to share its data around the web.

Twitter’s newly-aggressive attitude has been widely compared to that of a true Silicon Valley giant, Apple, and even prompted speculation that an acquisition could be on the cards.

It has also, however, provoked strong criticism from web developers and is said to have helped trigger the resignation of Mike McCue from Twitter’s board earlier this month. Mr McCue is chief executive of Flipboard, a popular mobile app that delivers news based on recommendations from social networking contacts.

Tumblr, the most recent victim of the cull, said it was “truly disappointed”.

“Given our history of embracing their platform, this is especially upsetting,” a spokesman said. “Our syndication feature is responsible for hundreds of millions of tweets.”

Marco Arment, a high-profile web developer and former Tumblr staff member, led the growing chorus of jeers this week.

“Twitter will now only permit large services to add value to Twitter, not get any value from it,” he said.

“So when Twitter says something like ‘[developers] will need to work with us’ to ‘identify areas of value’ when they get big enough for Twitter to notice, I don’t have high hopes for what ‘working with us’ might actually entail.”

As well as cutting off major websites, Twitter has also cracked down on small scale developers by rewriting the rules that allow their products to interact with it. Under the new rules, outside applications that display tweets are not allowed to have more than 100,000 users, display messages alongside content from other web services or compete with Twitter’s own software.

“The solution Twitter has taken involves barricading the walled garden, keeping the valuable tweet data inside Twitter, and removing all incentives for people to move to other, similar platforms,” said Dustin Curtis, the developer of Svbtle, a blogging network.

“The problem with this solution is that Twitter was built on the backs of the very developers it is now blocking.

“It now expects those developers to continue supporting Twitter by syndicating content into its platform, but it no longer wants to provide any value to developers in return.”

The motivation behind Twitter’s moves is clear, however. By raising the drawbridge on its only unique asset – the data its holds on members – Twitter aims to safeguard its growth by stopping outsiders selling advertising with its help.

Although it is six years old and one of the leading lights of the web, with more than 200 million members, the privately-held firm remains dependent on its large reserves of venture capital. Internal forecasts reportedly claim sales will reach $1bn in 2014 which would mean rapid scaling of its fledgling advertising business, which it’ is estimated brought in $140m last year.

It’s an ambitious goal. Facebook, which has roughly five times Twitter’s membership, is yet to build a significant advertising business on smartphones, where Twitter gets most use. Commentators including Mr Curtis argue that Twitter is more suited to small screens and an intrinsically better as an advertising medium, but as with developers, web users can be fickle.